I've got a lab of 2011 iMacs 27" that can only be upgraded to High Sierra. This year they can run CC2020 (but in paticularly I only really care about Photoshop and Illustrator ). Now, imagine CC2021 turns out to not support High Sierra. In that scenario, would the iMacs still be able to run CC2020 as long as I deem their performance adequate? Or, will Adobe CC not allow this and force the old iMacs to upgrade to a version even though it is incompatible with High Serria?